Effects of Heavy Metals Pollution on Some Fish and Mollusc Species from Port Sudan, Sudan
Issra Mohammed Osman Mahjoub,
Mohamed Elamin Hamza
Issue:
Volume 8, Issue 3, September 2020
Pages:
33-39
Received:
24 June 2020
Accepted:
4 November 2020
Published:
16 November 2020
Abstract: The effects on fishes Lethrinus harak and Cephalopholis minata and on the mollusc Tridacna maxima exposed to different concentrations of heavy metals vanadium, nickel, and copper were investigated. The study indicated that the LC50 for nickel were 198.200 ppm, for L. harak, 196.041 ppm for C. minata and 198.200 ppm for T. maxima. The LC50 for copper were 197.175 ppm for L. harak, 272.932 ppm for C. minata and 272.841 ppm in T. maxima. However, LC50 for vanadium recorded 131.836 ppm for L. harak, 164.769 ppm for C. minata and 164.037 ppm for T. maxima. On the other hand, LT50 due to nickel exposure recorded 74.815, 47.963, and 95.116 hours, for L. harak, C. minata and T. maxima, respectively. LT50 due to copper recorded 35.041, 47.681, and 71.835 hours for L. harak, C. minata and T. maxima, respectively. However, LT50 for vanadium were 11.989, 47.511 and 5.792 hours for L. harak, C. minata and T. maxima, respectively. In this study no response was detected in lower concentrations of nickel and copper i.e. 4 ppm and 32 ppm, however a high response was detected with the same concentrations of vanadium. The study indicated that T. maxima, was more tolerant for heavy metals pollution than L. harak and C. minata. Nickel concentrations detected in tissues analysis were 0.561-0.04 ppm, 0.421-0.02 ppm and 0.871-0.03 ppm for L. harak, C. minata and T. maxima, respectively. While copper concentrations recorded 1.1030-0.09 ppm, 0.4060-0.02 ppm and 1.35-0.03 ppm for L. harak, C. minata and T. maxima, respectively. However, vanadium concentrations, recorded 0.010-0.00 ppm, 0.04-0.014-0.01 ppm and 0.042-0.00 ppm for L. harak, C. minata, and T. maxima, respectively.
Abstract: The effects on fishes Lethrinus harak and Cephalopholis minata and on the mollusc Tridacna maxima exposed to different concentrations of heavy metals vanadium, nickel, and copper were investigated. The study indicated that the LC50 for nickel were 198.200 ppm, for L. harak, 196.041 ppm for C. minata and 198.200 ppm for T. maxima. The LC50 for coppe...
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Soil Physico-Chemical Property Characterisation Along with Different Land Use System in Gurage Zone, Southern Ethiopia
Kedir Jemal,
Henok Tesfaye
Issue:
Volume 8, Issue 3, September 2020
Pages:
40-47
Received:
23 June 2020
Accepted:
18 September 2020
Published:
16 November 2020
Abstract: Nowadays the impact of land use change on different natural and manmade resources including soil resources is getting increased attention globally. Information about impact of land use systems on soil physico-chemical properties is crucial for best land management practices. This study was, therefore, conducted to assess the impact of land use/land cover on the physicochemical properties of soils of wudma area, southern Ethiopia. The land use systems studied included grazing land, cultivated land, eucalyptus plantation and natural forest. The research was superimposed on land use systems that were located nearby on similar soil. Undisturbed core and disturbed composite soil samples were collected randomly with four replications for each land use system. The influence of land use systems on soil properties were analysed using the analysis of variance general linear model procedure of SAS software. Mean differences due to land use, were identified using The Least Significant Difference (LSD) test after differences were found statistically significant. The results showed that most of the soil physicochemical properties varied with land use systems. For instance soil texture, bulk density, pH (H2O), OM, Total N, available p, CEC, exchangeable K, studied were significantly affected (P ≤ 0.05 and/or P ≤ 0.01) by land use. In contrast, silt, total porosity, exchangeable Na, carbon to nitrogen ratios, was not significantly (P > 0.05) different due to land use. Generally, comparisons between cultivated on one hand and the forest, eucalyptus and grazing lands on the other revealed a highly significant difference on soil fertility parameters. For instance the highest mean values of pH, OM and CEC, TN, Ca and Na were observed in the surface of forest land soil with (6.4, 8.1, 75 cmol (+) kg-1, 0.4, 60, 0.84 cmol (+) kg-1) were observed under the forest land as compared to the lowest values (5.6, 3.8, 35 cmol (+) kg-1, 0.19, 14 and 0.48 cmol (+) kg -1) in the cultivated land respectively. The results of study showed that forest clearing and subsequently cultivation and tillage practices resulted in the decline of the soil quality and these changes effects on soil sensitivity to degradation and erosion. Therefore, reducing the intensity of cultivation and adopting integrated soil fertility management could maintain the existing soil condition and replenish the degraded soil properties of the area.
Abstract: Nowadays the impact of land use change on different natural and manmade resources including soil resources is getting increased attention globally. Information about impact of land use systems on soil physico-chemical properties is crucial for best land management practices. This study was, therefore, conducted to assess the impact of land use/land...
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